2ON3

A structural insight into the inhibition of human and Leishmania donovani ornithine decarboxylases by 3-aminooxy-1-aminopropane

Summary for 2ON3

• Entry DOI: 10.2210/pdb2on3/pdb
• Related: 2OO0
• Descriptor: Ornithine decarboxylase, 3-AMINOOXY-1-AMINOPROPANE (2 entities in total)
• Functional Keywords: beta-alpha-barrel, sheet, lyase
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 2
• Total formula weight: 102586.29

Authors

Dufe, V.T.,Ingner, D.,Heby, O.,Khomutov, A.R.,Persson, L.,Al-Karadaghi, S. (deposition date: 2007-01-23, release date: 2007-07-17, Last modification date: 2023-12-27)

Primary citation

Dufe, V.T.,Ingner, D.,Heby, O.,Khomutov, A.R.,Persson, L.,Al-Karadaghi, S.
A structural insight into the inhibition of human and Leishmania donovani ornithine decarboxylases by 1-amino-oxy-3-aminopropane.
Biochem.J., 405:261-268, 2007

PubMed Abstract: The critical role of polyamines in key processes such as cell growth, differentiation and macromolecular synthesis makes the enzymes involved in their synthesis potential targets in the treatment of certain types of cancer and parasitic diseases. Here we present a study on the inhibition of human and Leishmania donovani ODC (ornithine decarboxylase), the first committed enzyme in the polyamine biosynthesis pathway, by APA (1-amino-oxy-3-aminopropane). The present study shows APA to be a potent inhibitor of both human and L. donovani ODC with a K(i) value of around 1.0 nM. We also show that L. donovani ODC binds the substrate, the co-enzyme pyridoxal 5'-phosphate and the irreversible inhibitor alpha-difluoromethylornithine (a curative agent of West African sleeping sickness) with less affinity than human ODC. We have also determined the three-dimensional structure of human ODC in complex with APA, which revealed the mode of the inhibitor binding to the enzyme. In contrast with earlier reports, the structure showed no indication of oxime formation between APA and PLP (pyridoxal 5'-phosphate). Homology modelling suggests a similar mode of binding of APA to L. donovani ODC. A comparison of the ODC-APA-PLP structure with earlier ODC structures also shows that the protease-sensitive loop (residues 158-168) undergoes a large conformational change and covers the active site of the protein. The understanding of the structural mode of APA binding may constitute the basis for the development of more specific inhibitors of L. donovani ODC.

PubMed: 17407445
DOI: 10.1042/BJ20070188

Experimental method

X-RAY DIFFRACTION (3 Å)